Fantasy football is a hobby which relies heavily on tendencies. It relies on data. Sometimes it simply relies on that "gut feeling" that makes for some of the best memories or biggest upsets. When rookies are brought into the picture, it makes the picture even cloudier. We know what they did in college. Oftentimes we know why NFL teams drafted them. But the reality is that we have no clue what they'll bring to the NFL until they lace up and take the field for the first time as a pro.
We are in an era when quarterbacks are more prepared for professional football than ever. Alongside this fact is the apparent boom in passing production. Rosters are seemingly deeper at the wide receiver position because the targets are increasing by the year. Running backs are splitting duties in most backfields, and more coaches aren't hesitating to reward the "hot hand" on a weekly basis. It's an exciting time in fantasy football, but at times it's equally frustrating trying to figure out who will rise above the rest each week.
But where does that leave us in 2015? Let's take a look at each skill position, and consider which rookies are the best poised to become fantasy assets for your roster.
Quarterbacks
1. Marcus Mariota, Tennessee Titans
2. Jameis Winston, Tampa Bay Buccaneers
3. Bryce Petty, New York Jets
4. Garrett Grayson, New Orleans Saints
5. Sean Mannion, St. Louis Rams
Truthfully, we're only dealing with two fantasy-relevant rookie quarterbacks in 2015. Marcus Mariota takes the edge at the position for the time being. Jameis Winston undoubtedly has better weapons at receiver, but his offensive line needs to improve drastically. Winston rarely looks to escape the pocket and has a penchant for creating turnovers. Mariota will likely reward fantasy owners with his legs, and he rarely allows defenses to pick him off. After Mariota and Winston, there is a severe drop-off in rookie options at quarterback. Bryce Petty leads the next tier simply because he's the most likely to see some playing time in 2015, though he'll have to bypass Geno Smith and Ryan Fitzpatrick. It's unlikely, but he doesn't have the same hurdles as Garrett Grayson (Drew Brees) or Sean Mannion (Nick Foles) -- both of who are also third on the depth charts of their respective teams.
Running backs
1. Melvin Gordon, San Diego Chargers
2. T.J. Yeldon, Jacksonville Jaguars
3. Ameer Abdullah, Detroit Lions
4. Todd Gurley, St. Louis Rams
5. Tevin Coleman, Atlanta Falcons
The top three running backs on this list will presumably be starters for their respective teams. Melvin Gordon and T.J. Yeldon will see action in Week 1. Ameer Abdullah is a shifty back whom many expect to fill the void left by Reggie Bush, but in fact Abdullah's size, burst, and hands make him more similar to former Lions running back Jahvid Best. He may not be built for a full-time workload each week, but he has the talent to succeed in a limited role. Although Todd Gurley may be the most exciting prospect on this list, he's missing time this offseason as he recovers from a torn ACL he suffered in November. Tevin Coleman has to recover from a hamstring injury before he can claim the No. 1 spot on Atlanta's depth chart. He and Devonta Freeman have yet to separate themselves from one another, but it's very possible that Coleman could be the starter early in the season.
Wide receivers
1. Amari Cooper, Oakland Raiders
2. Nelson Agholor, Philadelphia Eagles
3. Breshad Perriman, Baltimore Ravens
4. DeVante Parker, Miami Dolphins
5. Devin Funchess, Carolina Panthers
Much like this season's running back list, there's a slight drop-off after the first several players on this list. Amari Cooper can be used inside and outside. He has the makings of a perennial high-volume target on any team he plays for. The question remains: Can the Raiders take advantage of their talented rookie? Nelson Agholor will be utilized to extend plays and create mismatches with his quickness in the middle of the field. Philadelphia is an ideal situation for someone with Agholor's skill set. Expect PPR production worthy of WR3 status right out of the gate. Breshad Perriman and DeVante Parker have plenty of opportunity, with each of their teams losing key playmakers at their position. Perriman is a raw talent who will need to become more disciplined in his route running to make a consistent fantasy impact. Parker will likely have a slow start after missing most of the offseason recovering from foot surgery. Devin Funchess has every opportunity to start alongside Kelvin Benjamin. His chances of seeing a good share of targets help him round out the list.
Tight ends
1. Maxx Williams, Baltimore Ravens
2. Clive Walford, Oakland Raiders
3. Tyler Kroft, Cincinnati Bengals
4. Jesse James, Pittsburgh Steelers
5. Blake Bell, San Francisco 49ers
Honestly, Maxx Williams and Clive Walford are the only rookie tight ends with enough upside to warrant a blip on your fantasy radar. Williams has struggled with the team's playbook this offseason, so it's likely he won't see much playing time early on. Crockett Gillmore is likely the starter for the Ravens, but he's a second-year player with plenty to prove. Williams has impressive burst and speed at 6'4 -- he could be a threat up the seam and in the red zone. Walford is being eyed as the starting tight end for the Raiders, but he's projected to be used more as a blocker in his rookie season. However, playing time can always lead to surprise production.
Beyond Williams and Walford, the remaining tight ends are ranked in order of opportunity. Tyler Kroft is behind Tyler Eifert on the depth chart. He's received some high praise from the Bengals coaching staff, but Kroft is on a roster full of receiving options. Jesse James is behind Heath Miller on Pittsburgh's roster, but Miller is turning 33 years old in October. James will be groomed as Miller's successor. It's also worth noting that the Steelers haven't pushed for tight end production in the receiving game. Blake Bell isn't an exciting prospect in terms of overall athleticism. However, the 49ers haven't seen much offensive production at the tight end position. Anything is possible if Vernon Davis can't get it together, as fellow tight end Derek Carrier deals with a foot injury.